In a conventional self-ballasted lamp having light-emitting portions each using an LED chip as a semiconductor light-emitting element, a light-emitting module, on which the light-emitting portions are mounted, and a globe for covering the light-emitting module are attached to one end side of a metallic base body, a cap is attached to the other end side of the base body via an insulating member, and a lighting circuit for supplying power to the LED chips of the light-emitting portions to light the self-ballasted lamp is housed inside the insulating member.
A light-emitting module is generally structured so that light-emitting portions are mounted on one face of a flat substrate, and the other face of the substrate is brought into face-contact with the base body and thermally-conductively attached to the base body.
While the self-ballasted lamp is lit, heat mainly generated by the LED chips of the light-emitting portions is conducted from the flat substrate to the base body and radiated into the air from a surface, which is exposed to the outside the base body.
Additionally, as a light-emitting module, a self-ballasted lamp exists in which, a plurality of light-emitting portions are arranged on a surface of a three-dimensional substrate formed in a globe, the three-dimensional substrate being formed of a regular-pyramid-shaped or cubic substrate or formed by bending a substrate in a sphere shape.
However, when the three-dimensional substrate is used for the light-emitting module, almost the entire light-emitting module is arranged in an air layer having a low thermal conductivity and only a part, which is supported, of the light-emitting module is connected to the base body. Accordingly, compared with the light-emitting module in which the flat substrate is thermally-conductively brought into face-contact with the base body, it becomes more difficult to efficiently conduct heat, which is generated by the LED chips of the light-emitting portions when the self-ballasted lamp is lit, to the base body. Therefore, the temperature of each light-emitting portion arranged in the air layer easily rises, and the life of each LED chip is shortened. Additionally, in order to suppress the temperature rise of the LED chips, power to be input to the LED chips is required to be reduced and light output is required to be suppressed.
Particularly, when a small mini-krypton type self-ballasted lamp is used, a base body is small in dimensions and sufficient radiation performance is hardly obtained from the base body. Therefore, not only in the case of using the three-dimensional substrate of the light-emitting module but also in the case of using the flat substrate of the module, a problem arises that sufficient radiation performance cannot be obtained only by thermal conduction to the base body.
The present invention has been made in view of the above problems and aims to provide a self-ballasted lamp capable of improving radiation performance, and lighting equipment.